Re: [Neo4j] [Neo] Transactions in Neo4j REST Server
Hi Jim, Yes, I mean controlling transaction lifecycle. Support for bulk uploading won't fit all my needs. I guess I'll have to write my own DB server for my own needs. MikKi 2010.10.29. 17:35 keltezéssel, Jim Webber írta: Hi MikKi, Transactions are everywhere in Neo4j, in fact each time you use the REST API a transaction wraps the work on the underlying graph store. I suspect you're wanting to control transaction lifecycle so that you can do bulk inserts for example? I have to say I'm not keen at all on exposing transactions outside the server, they're a database thing not a network thing (influenced by Pat Helland's work: http://msdn.microsoft.com/en-us/library/ms954587.aspx). However I would like to see the ability to do bulk uploads and I want to design that into the REST API in the future. I don't have any timescales around this specifically, but I am now a full time committer to Neo4j and I'm focussing my efforts on creating a server product that fulfils these kind of ambitions (since I share them), and other more mundane, but critically important, aspects like alerting, monitoring, etc. However, in the short term (hopefully in the current snapshot release due out in a week) there'll be the option to register your own code at a URI on the server. If you can't wait for me to get on to it, then in the meantime you should easily be able to write your own bulk uploader and host it on the Neo Server. Jim ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] [Neo] Transactions in Neo4j REST Server
Hey MikKi, Could you elaborate a bit more on your use case? If you want transaction control then perhaps it's widespread enough that other folks would want it too. Jim On 2 Nov 2010, at 09:16, Kiss Miklós wrote: Hi Jim, Yes, I mean controlling transaction lifecycle. Support for bulk uploading won't fit all my needs. I guess I'll have to write my own DB server for my own needs. MikKi 2010.10.29. 17:35 keltezéssel, Jim Webber írta: Hi MikKi, Transactions are everywhere in Neo4j, in fact each time you use the REST API a transaction wraps the work on the underlying graph store. I suspect you're wanting to control transaction lifecycle so that you can do bulk inserts for example? I have to say I'm not keen at all on exposing transactions outside the server, they're a database thing not a network thing (influenced by Pat Helland's work: http://msdn.microsoft.com/en-us/library/ms954587.aspx). However I would like to see the ability to do bulk uploads and I want to design that into the REST API in the future. I don't have any timescales around this specifically, but I am now a full time committer to Neo4j and I'm focussing my efforts on creating a server product that fulfils these kind of ambitions (since I share them), and other more mundane, but critically important, aspects like alerting, monitoring, etc. However, in the short term (hopefully in the current snapshot release due out in a week) there'll be the option to register your own code at a URI on the server. If you can't wait for me to get on to it, then in the meantime you should easily be able to write your own bulk uploader and host it on the Neo Server. Jim ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] [Neo] Transactions in Neo4j REST Server
I'm still in designing phase of my system so I have no specific situations yet. I think that transactions would be required for me to do the following as 1 atomic operation: - create a (few) new nodes - link the nodes into the graph - add indices - change some other node properties If at any point one operation fails it should cancel all the others (like ACID transactions in simple neo4j do). Or can this be done as a bulk upload? If so, how can cancelling be done? MikKi Hey MikKi, Could you elaborate a bit more on your use case? If you want transaction control then perhaps it's widespread enough that other folks would want it too. Jim On 2 Nov 2010, at 09:16, Kiss Miklós wrote: Hi Jim, Yes, I mean controlling transaction lifecycle. Support for bulk uploading won't fit all my needs. I guess I'll have to write my own DB server for my own needs. MikKi 2010.10.29. 17:35 keltezéssel, Jim Webber írta: Hi MikKi, Transactions are everywhere in Neo4j, in fact each time you use the REST API a transaction wraps the work on the underlying graph store. I suspect you're wanting to control transaction lifecycle so that you can do bulk inserts for example? I have to say I'm not keen at all on exposing transactions outside the server, they're a database thing not a network thing (influenced by Pat Helland's work: http://msdn.microsoft.com/en-us/library/ms954587.aspx). However I would like to see the ability to do bulk uploads and I want to design that into the REST API in the future. I don't have any timescales around this specifically, but I am now a full time committer to Neo4j and I'm focussing my efforts on creating a server product that fulfils these kind of ambitions (since I share them), and other more mundane, but critically important, aspects like alerting, monitoring, etc. However, in the short term (hopefully in the current snapshot release due out in a week) there'll be the option to register your own code at a URI on the server. If you can't wait for me to get on to it, then in the meantime you should easily be able to write your own bulk uploader and host it on the Neo Server. Jim ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] [Neo] Transactions in Neo4j REST Server
Hi all, I'd like to ask about the status of neo4j REST transaction support. I'm using 0.8 and as far as I know it doesn't support it. Will it be supported sometime in the near future (beginning of 2011)? Or shall I search for something different than neo4j? Regards, MikKi 2010.05.20. 21:05 keltezéssel, Rick Bullotta írta: Sounds a lot like code ;-) Rick -Original Message- From: user-boun...@lists.neo4j.org [mailto:user-boun...@lists.neo4j.org] On Behalf Of Tobias Ivarsson Sent: Thursday, May 20, 2010 2:55 PM To: Neo user discussions Subject: Re: [Neo] Transactions in Neo4j REST Server Hi buddies! My vote is for adding support for posting a batch of operations to be executed within the context of one transaction. What we need to figure out is how these should be expressed. Starting from a list of requirements is usually a good idea. The features I can think of that the batch operations should be able to do is: * Create nodes * Create relationships * Assign/update/remove properties * Verify assumptions The verification of assumptions is the trickiest part. The easies way I can think of for doing this is to have the client read all interesting state using the current API, then build a set of operations to post to the server, including a set of pre-conditions that need to validate for the transaction to be executed. If the operations fail the response will contain the failing conditions and the client can either drop the request or create a new request, either from scratch or based on the previous one and the information about the failing conditions. It might be more useful though to allow the operations to read state and decide on actions based on that. But supporting that is much harder, the set of operations is starting to approach a script in some programming language at that point. Like dr Webber I believe that allowing for client side (explicit) transaction management will lead to resource starvation. Just the thoughts I've been having around this, WDYT? Cheers, Tobias On Thu, May 20, 2010 at 5:51 PM, Kevin Raisonrai...@chatsubo.net wrote: I am in a situation where being able to bulk upload an ntriples-like file or perhaps a large JSON data blob via the REST interface as a single transaction would be incredibly helpful. Consider this a feature request. Thanks for your work on this! Cheers. Kevin On 5/20/10 6:14 AM, Jim Webber wrote: Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Kevin Raison Founder, CTO Chatsubo.net, LLC 9708 1st Ave NW Seattle, WA 98117 rai...@chatsubo.net ph: +1 (206) 801-5728 fx: +1 (206) 801-5729 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] [Neo] Transactions in Neo4j REST Server
Hi MikKi, Transactions are everywhere in Neo4j, in fact each time you use the REST API a transaction wraps the work on the underlying graph store. I suspect you're wanting to control transaction lifecycle so that you can do bulk inserts for example? I have to say I'm not keen at all on exposing transactions outside the server, they're a database thing not a network thing (influenced by Pat Helland's work: http://msdn.microsoft.com/en-us/library/ms954587.aspx). However I would like to see the ability to do bulk uploads and I want to design that into the REST API in the future. I don't have any timescales around this specifically, but I am now a full time committer to Neo4j and I'm focussing my efforts on creating a server product that fulfils these kind of ambitions (since I share them), and other more mundane, but critically important, aspects like alerting, monitoring, etc. However, in the short term (hopefully in the current snapshot release due out in a week) there'll be the option to register your own code at a URI on the server. If you can't wait for me to get on to it, then in the meantime you should easily be able to write your own bulk uploader and host it on the Neo Server. Jim ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
What I don't like about uploading a block of code (in whatever format/language) to pose as a transaction is that transactions don't become transparent as they would be if you would use an embedded instance. You can't just do: Oh, wait I should've put the transaction handling THERE in my application instead, it makes more sense. Instead you must know before-hand all your transaction points and it gets harder to change those later on. You also must write your code (be it PHP or whatever) differently if it will be grouped in transactions or not, unless you use some kind of library on top of the REST API which could mimic that grouping behaviour for you. Uploading a block of code to execute on the server could be cool as well, but I don't see that as the only way of doing bigger-than-one-operation transactions. 2010/5/20 Tobias Ivarsson tobias.ivars...@neotechnology.com: It does, doesn't it ;-) And I'm trying to keep the code as simple as possible... .. because for really complex things I think that uploading real code to the server and mount it on a separate URI in the REST server would be more efficient ... -tobias On Thu, May 20, 2010 at 9:05 PM, Rick Bullotta rick.bullo...@burningskysoftware.com wrote: Sounds a lot like code ;-) Rick -Original Message- From: user-boun...@lists.neo4j.org [mailto:user-boun...@lists.neo4j.org] On Behalf Of Tobias Ivarsson Sent: Thursday, May 20, 2010 2:55 PM To: Neo user discussions Subject: Re: [Neo] Transactions in Neo4j REST Server Hi buddies! My vote is for adding support for posting a batch of operations to be executed within the context of one transaction. What we need to figure out is how these should be expressed. Starting from a list of requirements is usually a good idea. The features I can think of that the batch operations should be able to do is: * Create nodes * Create relationships * Assign/update/remove properties * Verify assumptions The verification of assumptions is the trickiest part. The easies way I can think of for doing this is to have the client read all interesting state using the current API, then build a set of operations to post to the server, including a set of pre-conditions that need to validate for the transaction to be executed. If the operations fail the response will contain the failing conditions and the client can either drop the request or create a new request, either from scratch or based on the previous one and the information about the failing conditions. It might be more useful though to allow the operations to read state and decide on actions based on that. But supporting that is much harder, the set of operations is starting to approach a script in some programming language at that point. Like dr Webber I believe that allowing for client side (explicit) transaction management will lead to resource starvation. Just the thoughts I've been having around this, WDYT? Cheers, Tobias On Thu, May 20, 2010 at 5:51 PM, Kevin Raison rai...@chatsubo.net wrote: I am in a situation where being able to bulk upload an ntriples-like file or perhaps a large JSON data blob via the REST interface as a single transaction would be incredibly helpful. Consider this a feature request. Thanks for your work on this! Cheers. Kevin On 5/20/10 6:14 AM, Jim Webber wrote: Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Kevin Raison Founder, CTO Chatsubo.net, LLC 9708 1st Ave NW Seattle, WA 98117 rai...@chatsubo.net ph: +1 (206) 801-5728 fx: +1 (206) 801-5729 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Tobias Ivarsson tobias.ivars...@neotechnology.com Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 ___ Neo
Re: [Neo] Transactions in Neo4j REST Server
Hi! The guys who wrote the REST component are offline at the moment, so I'll just chime in here for now. You are right that the current REST API won't allow you to control transactions: it wraps each request in a transaction. There's basically two strategies, either you keep a transaction open spanning multiple requests, or you bundle the operations together somehow and send them in a single request. It would be interesting to hear some different views on this topic from the community - what would be useful to you? /anders Javier de la Rosa wrote: Hi all, I think there's no way to perform a transaction through Neo4j REST Server. It would be great if we could emulate this behaviour using the header Keep-Alive, some session variable or some persistence issue. A good option can be the next (I'm guessing Neo4j isn't able to manage several transactions simultaniously, but I don't really know): Create transaction POST /transaction Example using curl $ curl -H Accept:application/json -X POST http://localhost:/transaction Response 201: OK, a transaction was created 409: Transaction already in progress Since that moment, whatever you do will be under the transaction. When you finish the transaction. the DELETE verb has to be invoked over /transaction: DELETE /transaction Example using curl $ curl -X DELETE http://localhost:/transaction Response 204: OK, no content returned 404: Transaction not found What do you think about this? Is it too many complicated? Is it possible? Best regards. ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
REST purists prefer that each REST-ful invocation is atomic, but as
we all know, there are definitely cases where multiple transactions
need to be implemented.
The cleanest approach I've seen involved an explicit call to create a
transaction/unit of work, and some type of transaction token/ID and/or
URL would be returned (a new URI resource) that would be passed as part
of subsequent REST-ful calls as either part of the URL or as a header.
Then, the original URI resource could be used to complete/rollback the
transaction [1]http://server/Neo4J/Transaction/87342342344/Commit or
[2]http://server/Neo4J/Transaction/87342342344/Fail.
I think Javier's proposal is similar, but what I would avoid is
inferring transactions between a client and server in the way Javier
describes, and instead making the transaction identifier a part of the
URL or delivered as a header.
I also like his approach of using well-known HTTP result codes to
manage the transaction lifecycle.
Rick
Original Message
Subject: Re: [Neo] Transactions in Neo4j REST Server
From: Anders Nawroth and...@neotechnology.com
Date: Thu, May 20, 2010 9:00 am
To: Neo user discussions user@lists.neo4j.org
Hi!
The guys who wrote the REST component are offline at the moment, so
I'll
just chime in here for now.
You are right that the current REST API won't allow you to control
transactions: it wraps each request in a transaction.
There's basically two strategies, either you keep a transaction open
spanning multiple requests, or you bundle the operations together
somehow and send them in a single request.
It would be interesting to hear some different views on this topic from
the community - what would be useful to you?
/anders
Javier de la Rosa wrote:
Hi all,
I think there's no way to perform a transaction through Neo4j REST
Server. It would be great if we could emulate this behaviour using
the
header Keep-Alive, some session variable or some persistence issue.
A good option can be the next (I'm guessing Neo4j isn't able to
manage
several transactions simultaniously, but I don't really know):
Create transaction
POST /transaction
Example using curl
$ curl -H Accept:application/json -X POST
[3]http://localhost:/transaction
Response
201: OK, a transaction was created
409: Transaction already in progress
Since that moment, whatever you do will be under the transaction.
When
you finish the transaction. the DELETE verb has to be invoked over
/transaction:
DELETE /transaction
Example using curl
$ curl -X DELETE [4]http://localhost:/transaction
Response
204: OK, no content returned
404: Transaction not found
What do you think about this? Is it too many complicated? Is it
possible?
Best regards.
___
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User@lists.neo4j.org
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References
1. http://server/Neo4J/Transaction/87342342344/Commit
2. http://server/Neo4J/Transaction/87342342344/Fail
3. http://localhost:/transaction
4. http://localhost:/transaction
5. https://lists.neo4j.org/mailman/listinfo/user
___
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Re: [Neo] Transactions in Neo4j REST Server
Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
Thank you all, your ideas are great. I guess to introduce some kind of pagination only make harder the work :-) but it continues being interesting. Best regards. -- Javier de la Rosa ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
Hi buddies! My vote is for adding support for posting a batch of operations to be executed within the context of one transaction. What we need to figure out is how these should be expressed. Starting from a list of requirements is usually a good idea. The features I can think of that the batch operations should be able to do is: * Create nodes * Create relationships * Assign/update/remove properties * Verify assumptions The verification of assumptions is the trickiest part. The easies way I can think of for doing this is to have the client read all interesting state using the current API, then build a set of operations to post to the server, including a set of pre-conditions that need to validate for the transaction to be executed. If the operations fail the response will contain the failing conditions and the client can either drop the request or create a new request, either from scratch or based on the previous one and the information about the failing conditions. It might be more useful though to allow the operations to read state and decide on actions based on that. But supporting that is much harder, the set of operations is starting to approach a script in some programming language at that point. Like dr Webber I believe that allowing for client side (explicit) transaction management will lead to resource starvation. Just the thoughts I've been having around this, WDYT? Cheers, Tobias On Thu, May 20, 2010 at 5:51 PM, Kevin Raison rai...@chatsubo.net wrote: I am in a situation where being able to bulk upload an ntriples-like file or perhaps a large JSON data blob via the REST interface as a single transaction would be incredibly helpful. Consider this a feature request. Thanks for your work on this! Cheers. Kevin On 5/20/10 6:14 AM, Jim Webber wrote: Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Kevin Raison Founder, CTO Chatsubo.net, LLC 9708 1st Ave NW Seattle, WA 98117 rai...@chatsubo.net ph: +1 (206) 801-5728 fx: +1 (206) 801-5729 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Tobias Ivarsson tobias.ivars...@neotechnology.com Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
Sounds a lot like code ;-) Rick -Original Message- From: user-boun...@lists.neo4j.org [mailto:user-boun...@lists.neo4j.org] On Behalf Of Tobias Ivarsson Sent: Thursday, May 20, 2010 2:55 PM To: Neo user discussions Subject: Re: [Neo] Transactions in Neo4j REST Server Hi buddies! My vote is for adding support for posting a batch of operations to be executed within the context of one transaction. What we need to figure out is how these should be expressed. Starting from a list of requirements is usually a good idea. The features I can think of that the batch operations should be able to do is: * Create nodes * Create relationships * Assign/update/remove properties * Verify assumptions The verification of assumptions is the trickiest part. The easies way I can think of for doing this is to have the client read all interesting state using the current API, then build a set of operations to post to the server, including a set of pre-conditions that need to validate for the transaction to be executed. If the operations fail the response will contain the failing conditions and the client can either drop the request or create a new request, either from scratch or based on the previous one and the information about the failing conditions. It might be more useful though to allow the operations to read state and decide on actions based on that. But supporting that is much harder, the set of operations is starting to approach a script in some programming language at that point. Like dr Webber I believe that allowing for client side (explicit) transaction management will lead to resource starvation. Just the thoughts I've been having around this, WDYT? Cheers, Tobias On Thu, May 20, 2010 at 5:51 PM, Kevin Raison rai...@chatsubo.net wrote: I am in a situation where being able to bulk upload an ntriples-like file or perhaps a large JSON data blob via the REST interface as a single transaction would be incredibly helpful. Consider this a feature request. Thanks for your work on this! Cheers. Kevin On 5/20/10 6:14 AM, Jim Webber wrote: Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Kevin Raison Founder, CTO Chatsubo.net, LLC 9708 1st Ave NW Seattle, WA 98117 rai...@chatsubo.net ph: +1 (206) 801-5728 fx: +1 (206) 801-5729 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Tobias Ivarsson tobias.ivars...@neotechnology.com Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo] Transactions in Neo4j REST Server
It does, doesn't it ;-) And I'm trying to keep the code as simple as possible... .. because for really complex things I think that uploading real code to the server and mount it on a separate URI in the REST server would be more efficient ... -tobias On Thu, May 20, 2010 at 9:05 PM, Rick Bullotta rick.bullo...@burningskysoftware.com wrote: Sounds a lot like code ;-) Rick -Original Message- From: user-boun...@lists.neo4j.org [mailto:user-boun...@lists.neo4j.org] On Behalf Of Tobias Ivarsson Sent: Thursday, May 20, 2010 2:55 PM To: Neo user discussions Subject: Re: [Neo] Transactions in Neo4j REST Server Hi buddies! My vote is for adding support for posting a batch of operations to be executed within the context of one transaction. What we need to figure out is how these should be expressed. Starting from a list of requirements is usually a good idea. The features I can think of that the batch operations should be able to do is: * Create nodes * Create relationships * Assign/update/remove properties * Verify assumptions The verification of assumptions is the trickiest part. The easies way I can think of for doing this is to have the client read all interesting state using the current API, then build a set of operations to post to the server, including a set of pre-conditions that need to validate for the transaction to be executed. If the operations fail the response will contain the failing conditions and the client can either drop the request or create a new request, either from scratch or based on the previous one and the information about the failing conditions. It might be more useful though to allow the operations to read state and decide on actions based on that. But supporting that is much harder, the set of operations is starting to approach a script in some programming language at that point. Like dr Webber I believe that allowing for client side (explicit) transaction management will lead to resource starvation. Just the thoughts I've been having around this, WDYT? Cheers, Tobias On Thu, May 20, 2010 at 5:51 PM, Kevin Raison rai...@chatsubo.net wrote: I am in a situation where being able to bulk upload an ntriples-like file or perhaps a large JSON data blob via the REST interface as a single transaction would be incredibly helpful. Consider this a feature request. Thanks for your work on this! Cheers. Kevin On 5/20/10 6:14 AM, Jim Webber wrote: Hi fellow graph-tastic people, Allowing a transaction to span multiple requests was ruled out in the early version of the REST API. It's a dangerous pattern that allows for inadvertent (or even malicious) denial of service. If we're going to build systems that sympathetic to the Web, then exposing transactions like this is not the way to go. Having said that, the REST API will need more functionality and that new functionality will need to address transactionality, but it will need to do so in a way that doesn't compromise its Web-iness. Rick's response is one approach, where a transaction is modelled as a resource; another approach might be to submit a transactional workflow through the API and get a result graph/set back. I promise I'll do some work on the API again soon. So start yelling your requirements and I'll prioritise them (and will ignore the ones that are too hard for me to implement, naturally :-) Jim ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Kevin Raison Founder, CTO Chatsubo.net, LLC 9708 1st Ave NW Seattle, WA 98117 rai...@chatsubo.net ph: +1 (206) 801-5728 fx: +1 (206) 801-5729 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Tobias Ivarsson tobias.ivars...@neotechnology.com Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Tobias Ivarsson tobias.ivars...@neotechnology.com Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo] Transactions in Neo4j REST Server
Hi all, I think there's no way to perform a transaction through Neo4j REST Server. It would be great if we could emulate this behaviour using the header Keep-Alive, some session variable or some persistence issue. A good option can be the next (I'm guessing Neo4j isn't able to manage several transactions simultaniously, but I don't really know): Create transaction POST /transaction Example using curl $ curl -H Accept:application/json -X POST http://localhost:/transaction Response 201: OK, a transaction was created 409: Transaction already in progress Since that moment, whatever you do will be under the transaction. When you finish the transaction. the DELETE verb has to be invoked over /transaction: DELETE /transaction Example using curl $ curl -X DELETE http://localhost:/transaction Response 204: OK, no content returned 404: Transaction not found What do you think about this? Is it too many complicated? Is it possible? Best regards. -- Javier de la Rosa ___ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
